Rotary pump or the like



H. G. BowERlNG noTAmrPUuP onI THE LiKE April 15, 1941.`

Filed Jan. 22, A193:8 2 4 Sheets-Sheet' 2 April 15, 1941. H, G. Bowl-:RING 2,238,552

ROTARY-PUMP OR THE LIKE Filed aan. 22, 1958 4 sheets-sheet `s f9.5 In vqntolf $0 by Hz'ower A April 15 1941- H. G. BowERlNG 2,238,552

ROTARY Puur' on 'rag LIKE Fileduan. 22, 1958 4 sheets-sheet 4 INVENIOR.

' 4M'TORNEYS.

Patented Apr. 125, 12941 ROTARY PUMP R THE LIKE edham, Mass., assigner to Henry G. Bowering, Ne

Kinney Manufacturi Plain, Mass., a corpora ng Company,

tion of Massachusetts Jamaica 'Application January :22, 1938, Serial No. 186,402

9 Claims.

. The invention herein discussed relates to rotary pumps and compressors and the like and is ap. plicable to such devices of various types.-

For the purpose of discussion and disclosure, I refer to certain difculties developed in pump service generally' and to their correction. Other features are'novel items of improvement in the general art as will be apparent to those skilled in its practices.

Pumping and like equipment according to my invention is intendedor various uses and in some installations as on oil tankers, they mayv be called upon to handle as different materials as cargo gasoline or salt water ballast after unloading. Such uses subject the rotors and associated interior parts to very severe wear requiring frequent replacements. Repairs or replacements mustfof course, be'made as quickly as possible with a minimum tie-up ofthe pump on which such a cargo carrierisso dependent.

The handling oi gasoline above cited, imposes a most exacting test on the tightness of the pumps. Leakage is not only costly -but dangerous to cargo and crew. This vhas led to serious packing problems. In eiorts toY keep packings tight, as on the pump shafts, they have been set up to limits which withA non-lubricating materials developed serious wear on the shaft and increased A and 22 aligned` with, each other at its opposite y leakage until replacement became necessary. In

pumps of intermeshing type. the inter-pocket pressures tend to become .very great. V Eiforts have been made to vent such pockets but without satisfactory results and usually with a serious Weakening of the rotor blades or teeth. l

My invention provides for relief both for pocket pressures or for packings or both.. As thev strain of the pump shaft increases with itslateral dimensions necessary or desirable for capacity, the matter of bearings becomes critical. Extended bearings, however, add to the complications of repair and replacement so that my invention contemplates new improvements which in large measure solve these conflicting difficulties.

While intended to beillustrative for. the purposes of disclosure and discussion, I have shown in the accompanying drawings structures of practical value from both manufacturing and operating aspects.

Fig. 1 is a view in partial central section of apump and drive in accordance with my invention.

Fig. 2 is a planeview of the same.

Fig. 3 is an end elevation showing the driving side of such equipment.

Fig. 4 is a view of the opposite side showing the buttons or bosses 34 whichk are stepped orv shouldered to register with the correspondingly f Fig. 9 is an edge view of one of such members.

Fig. 10 is a small general view illustrative of another disposition of a pump with intake and discharge with y rotors superimposed.

Fig. 1l is an enlarged section of the pump unit at the left of Fig. 1. i y

In the form of equipment herein shown -I provide a baseeor bed i adapted to be anchored to any stable foundation and carrying an intake casing 20 Vhaving flanged Aintake connections 2i sides, onevbeing shown as closed*l by a plate 22' in favor of the use of the other opening, although pumps may be designed to utilize both of' such intakes.

Mounted on the top of the casing 20 and covering its central upward passage 23 is a double 4rotor casing 30 having a flanged upwardly directed discharge 40 connecting with the rotor casing .interior centrally of its opposite interior rotor chambers 3| and 32.

On one side the casing 30 is formed with an opening inclusive of thechambers 3l and 32 and covered with a removable cover plate 33 so that the interior may be readily accessible for assembling or replacing the rotors without disturbing any packngs or shaft `bearings on lighter or smaller sizes.

The pair of rotors f 50 are preferably of the helical blade and groove'type, 'and formed with inclined intermeshing members (Figs. 5 and 6). This, as will later reappear; permits their disengagement and withdrawal or replacement through the open side of the casing 30 by simply removing the cover plate 33 in "smaller sizes of pumps. On its inner face the covery plate 33 is fitted with inwardly projecting buttons or bosses 34 having shouldered or stepped inner end portions 35.

The rotors 50 are diametrically undercut as at 52 on their outer faces next the plate 33 to a dimension equal to the diameter' of the hub at the base of the blades to a suitable depth to receive stepped or shouldered portions 35 of the rotor ends, thus forming an indirect or labyrinthine joint.

On their opposite faces the rotors 56 are diametrically undercut as at 5'2 to a dimension equal to the diameter at the base of the blades to a suitable depth to receive oppositely disposed cylindrical buttons or bosses 36 adjustably bolted to a cover plate 51 on the Wall of the rotor casing 3D opposite to the cover plate 33.

The buttons or bosses 34 and 36 have sufficient clearance between their outside diameter and the diameter at the base of the blades to prevent these bosses acting as supports for the overhanging ends of the rotors. The projected area of each button, i. e. outside boss diameter times boss length, is subtracted from the total projected area of the rotors, which results in a reduction in projected area of the rotors. This reduction in projected area reduces the amount of shaft deiiection and load to be supported by the pump bearings. This is made possible by the fact that the undercutting of the rotor ends as at 52 to a dimension equal to its diameter at the base of the blades 5I (see Fig. 6) leaves the ends of the blades overhanging the central cylindrical portion of the rotor 50 through which the shaft 53 passes. These overhanging ends of the blades 5| have their developed pressures backed up without having actual contact, by the buttons or bosses 36 and 34. These portions ll the otherwise empty concavity at the rotor end and so permit the cutting away of the rotor to the base of the rotor blades until they actually are left overhanging. Thus internal pressures are not bottomed on'the ro'tor surface between the blades, but are bottomed at their end areas by' the fixed buttons or bosses 34 and 36 on the casing which 'can thus take up the internally developed pressures without having any stress orstrain develop through the rotor on its shaft or bearings. '.Ihis permits reductions in the pro-'l jected load area in' very considerable amounts with a considerable saving of power in operag tionl and without increased expense in structures for resisting high pressures. v

The rotors 5U 'are thus overhung at their 'sides or ends making possible the width of lateral di'- rnension togprcvide full desired capacity and thus permit of operating at higher outlet of the pump. f

Each rotor is mounted on a shaft 53 or 53' entered through the back wall of the casing 30 and guarded against leakage by a longpacking 54 set up by a split gland 55 by threaded T- shaped swing bolts 56.

As will be understood from consideration of Fig. 11, the boss 36 shown at the right of the figpressures at the ure. has a plurality of functions. Not only does I it fill the cavity in the end of the rotor to take up the projected pressure load removed from the rotor shaft by removal of the hub portion of the rotor as above described, but it also serves as the'outer Wall of the stuffing box for the packing 54, the inner wall of which stuffing box is the sleeve 31 xed on the shaft 53. The boss 36 is formed with an inwardly turnedring portion 36a which contacts the slightly outwardly turned edge 31a of the sleeve 31 to close the end of the stuffing box adjoining therotor chamber to separate the packing Afrom-` the rotor chambers 3I-32. i

As shown in'Fig. 11, the outer ends of the bosses 36 areshouldered as at 36.' to receive a collar 38 which'isv bolted to the cover plate 51 which in turn is bolted to the casing 30. The collar 3B yholds the boss 36 firmly in place with the packing 54 pressed within -the stuffing box formed by the boss 36 and sleeve 31 as above described.

It being very important, as previously pointed out, to avoid leakage, as when pumping `gasoline or other volatile materials, the tendency has been to set up such packings and stuffing boxes very tight with the result where non-lubricating fluids such as the gasoline above instanced or salt water ballast were pumped, the shafts were rapidly worn. v y

'I'his dimculty I avoid by drilling or otherwise forming small vents or ducts 56 leading from the end 36a of the boss 36 forming the stufiing box for the packing l54 (Figs. 1 and 11) transversely of the rotor and opening into a chamber 562 which is piped as at 58` to the inlet side whereby the pressures on the packings 54 may be adjustably reduced or neutralized by a valved control to inlet'pressure (Figs. 1 and 11) and the packings need not be set up so close as to generate the old excessive wear. The valve 58' controlling the venting of the pipe 58 may be of any desired type, that shown being simply a shut-off valve controlled by a hand wheel (see left of Fig. 11.)

By means of this arrangement, it is possible to avoid the former damaging end pressures on the packing. As will be apparent from Fig. 11, I provide an internal discharge communicating with the labyrinth grooves leading from the rotor chambers vbetween the cut out 'rotor ends and bosses, this discharge beginning at the innerfend of the stufng box and leading back tol the suction sideL of the pump.' Liquid under pressure will pass through the labyrinth'groove's and the internal passage or vent 56' to the suc tion chamber 562 with a continuous dropain pressure throughout the course of the flow. By thismeans, the hydraulic pressure on the inner end of the packing 54 is reduced, thus overcoming the necessity of maintaining the packing as tight as otherwise would be necessary so that the life of the packing is 'increased'and weary on the shaft decreased.

The rotor shafts tomy invention in bearings externally of the rotor casing and hence need not be disturbed in making repairs or replacements in the pump interior, except in very large sizes of pumps. One of the shafts 53 see Fig. 1) may be called the main shaft as it is extended through the i gear housing 6I for connection'through coupling or other means to a source of motive power. The shaft of the companion rotor may be called the auxiliary shaft and is indicated at 53 to disinguish it from the so-called 'main shaft from which it is driven through the gears 60. As this type of pump is most efficiently made and operated without actual contact engagement of the rotor surfaces, I provide means for driving the auxiliary rotor shaft by intergearing as by a pair of pinions 60 which transmit from one shaft to the other the power necessary to drive one of the rotors without transmission duty on the blades. The pinions are mounted between bearings in the frame 6|, preferably exterior to and independent of the rotor casing 30 but in stable mounting on rthe pump base.

As such it may be a unit of individual adjustment and easy assembly or replacement in case of accident.- In the frame 6| I can provide high efficiency 53 aresupported according bearings such as the roller bearing 62 and radial geously smooth action and is 4very versatile in its n thrust ball bearings 63. The rotor shaft 53 is suitably coupled to a power drive, -regard of course being had for direction of rotation of the rotors.

As shown the casing 6I is indicated as detachably yoked or braced as at 64 to the main casing 30.

While almost any type of rotor can be used within the indicated pumping improvements of my present invention, I have devised aform of angular blade which in rotation permits a maximum period of filling and discharging of the bucketlike channels formed by the blades.

While pumps according to myl invention are built with simple unlined casings, in certain types it is extremely desirable to fit the rotor areas of the casing with liners and in the drawings I have shown the pump so fitted in a simple and advantageous manner.

As the matter of clearance for the rotor blades and casing walls is important, I provide for the semi-cylindrical members 3l and 32 of the casing liner members 'I0 (Fig. 7). These are cylindrically curved externally to conform to the inner face of the casing wall and have an inner bore 1l accurately finished as a cylindrical unit and then divided to give the desired clearance with the rotor blades by being pinned in place,y

as indicated in Fig. 1. I

I also may provide lateral liner members (Figs. 8 and 9) which are accurately turned as discs on a radius R and apertured as at 8| for shaft clearance. By turning' to the radius of the chambers of the double rotor casing and simply facing off as at 82 on the chord line X-X coinciding withthe plane Abisecting the zone of rotor tooth lnterengagement, I provide for a very accurate and practical lining at the rotor ends (Figs. '7, 8 and 9). A

The bosses 3l and 36 have still another function in connection with these end liners 80. As

shown in Fig. 11, the bosses V34 and 36 have shoulders 34h and-36h respectively on their outer faces. The liners 80 are slipped over the bosses through their apertures 82 yand bear thereon against the shoulders 34h and 36h, being rmly held in place by the bolts fastening the end plates 33 and 51 to the casing 30. The ring 38'bolted to the end plate 51 holds the boss 36 in place.

The disposition' of the rotor pair may be vertical or superimposed as shown in Fig.`1'0 but usually is set up side by side as in Figs. 1 to 4.

In the vertical or superimposed form` the casing has less tendency to dra-in and so is advantageous in many installations. As disclosed in Fig. 10, a casing 200 has an intake 20| and delivery 202 from rotors on its shafts 203. Where mounted as a deck pump for tanks in a deep hold, this position is of advantage as not requiring priming of the casing should it become drained when` emptying. a deep tank which in the case of a cargo like .gasoline should not only be emptied but be scavenged as far as possible.

The rotor shown in Fig; 6 is indicated as having five blades 5| but rotors with three blades or four or even more. than five are entirely satisfactory depending on the width and diameter of the rotors. It is only necessary that the helix angle at the mean diameter be such that there is at least one angular blade on each rotor acting as a closure in each chamber of the double rotor casing between the inlet and outlet connection of the pump chamber. As before stated, the helical bladed rotor shows an advantapulverulent materials.l However, my invention is applicable to pumps of the old gear types and these are greatly improved by my concept of overhang and also my venting of vadjacent; stuffing boxes or packings.

My ability by my invention to provide external bearings is of great advantage, but my other features are capable of use in pumps having interior bearings. While I prefer for most purposes that all my rotor surfaces have free clearance and be carried on their shafts, I can utilize my interior buttons or bosses on which the rotors are overhung as actual rotor bearings. When used as such the overhanging portion of each rotor is fitted with babbitt or other antifriction metal inserts.

Allv these and many other modifications in combination and structure will be apparent to those skilled in pump design from the illustration and instruction herein given. In the claims,

for the sake of brevity, I have referred to my devices as pumps, but it will be understood that this is meant to be a term generally inclusive of pumping and compressive devices.

What I. therefore claim and desire to secure by Letters Patent is:

1. A pump of the class described comprising a double rotor casing having inlet and outlet passages and intersectingchambers communieating -with said passages, intermeshing 'bladed rotors in said chambers, a shaft for each rotor extending through said casing, each of said rotors-comprising a hub and a plurality of blades extending from said hub, the hubl portions at the end of said rotors being removed to vreduce v Athe projectedload area carried by the rotor shafts and to leave cavities over which the ends of said blades overhang, removable end plates secured to said casing, at least one of said plates being outwardly spaced from said rotor ends to provide a suction vchambenbosses rigidly connected to and projecting inwardly from saidend plates and extending into said cavities at the rotor ends beneath said overhanging blades to receive the projected load removed from the vrotor shafts by the removalof the hub Vends and with the walls of said cavities providing grooves leading from said chambers, means defining with one of said bosses a stuiling box, a packing in said stufling box about one of said shafts, and means leading from said grooves to said suction chamber and to the suction intakel of the pump whereby pressures escaping from the rotor chambers past said boss are diverted from said packmg.

2. The pump of claim 1, the means leading from said grooves to the suction intake of the pump comprising a passage extending transversely through said rotor.

3. A pump of the class described comprising a double rotor casing having inlet and outlet passages and intersecting chambers communicating with said passages, intermeshing bladed rotors in said chambers, a Vshaft for eachrotor extending through said casing, each of said rotors comprising a hub and a plurality 'of blades extending from said hub, the hub portions at the end of said rotors being removed to reduce the projected load area carried by the rotor shafts and to leave cavities over which the ends of said blades overhang, removable end plates outwardly spaced from said rotor ends and secured to said casing,

bosses projecting inwardly from said end plates and extending into said cavities to receive the projected load removed from the rotor shafts by removal of said hub portions, said cavities and said bosses being similarly stepped and shou1- dered to provide labyrinth grooves leading from said rotor chamber, means defining with one of said bosses a stufling box, a packing in said stuifing box, and means communicating with said labyrinth grooves and with the suction side of the pump whereby pressures. escaping from the rotor chamber through said grooves are diverted from said packing.

4. The pump of claim 3, the means communicating with 'the labyrinth grooves and with the suction side of the pump comprising lateral passages extending transversely through th-e rotors.

5. A pump of the class described comprising a double rotor casing having inlet and outlet passages and intersecting chambers communicating with said passages, intermeshing bladed rotors in said chambers, a shaft for each rotor extending through said casing, each of said rotors comprising a hub and a plurality of blades extending from said hub, removable end plates outwardly spaced from said rotor ends and secured to said casing, bosses projecting inwardly from said end plates, said hub ends and bosses being interengaged to provide labyrinth grooves leading from said rotor chamber, means on at least one of said shafts defining with one of said bosses a stuiiing box, a packinginsaid stuffing box, and a passage communicating with said labyrinth grooves and one of'said hub ends and extending transversely" through said rotor from the end of' said stufng' box to the suction side of the pump whereby pressures escaping from the rotor chamber through said grooves are diverted 'from said packing. v t

6. A pump of the class described comprising a double rotor casing having inlet and outlet pas-- sages and intersecting chambers communicating.

With said passages, intermeshing bladed rotors in said chambers, a shaft for each rotor extendingV through said casing, each of said rotors comprising a hub and a plurality of blades extending from said hub, removable Iend plates outwardly spaced from said rotor ends and secured to said casing, bosses projecting inwardly from said end plates, said hub ends and bosses being interengaged to provide labyrinth grooves leading from said rotor chamber, La packing on each shaft and spaced from said rotor chamber by one of said bosses, and a passage communicating with said grooves and extending fromthe chamber side of said last named boss and a conduit from said chamber to the suction intake of the pump whereby pressures escaping from the rotor chamber through said labyrinth grooves are diverted from said packing.

'7. The pump of claim 5 and liners between said rotors and end plates and mounted on. said bosses, one of said bosses including means spacing the liner mounted thereon from the adjacent rotor end to provide a suction chamberV intermediate said passage and the suction side of the pump.

8. A pump comprising a casing, a rotor having a hub in saidtcasing, a shaft for said rotor entrant through one side of said casing, said casing having a pair of boss portions, said boss portions and the ends of said hub being formed with complementa] surfaces defining labyrinth grooves, a shaft packing exteriorly of the complemental surfaces adjacent the shaft entering side of said casing, the opposite side of said casing having an annular recess to receive the other end of said hub arid defining therewith a chamber for leak- 4 age through the adjacent groove, transverse bores through said hub effecting communication between said chamber and the other groove, and a conduit in communication with said chamber and the suction side of said pump to effect the positive withdrawal of leakage and the like away from said packing. n l E 9. A pump comprising'a casing, a rotor hav? ing a hubin said casing, a shaft for said rotor, a pair of bosses carried by said casing, said bosses and said hub being formed with complemental surfaces defining labyrinth. grooves, a shaft packing exteriorly ofthe complemental surfaces de.

lined by one of said bosses and one end of said hub, the other of said bosses dening with the other end of said hub a chamber, transverse bores.

through said hub effecting communication between said chamber and said first named boss, and a conduit in communication with said chamber and the suction side of said pump to draw positively leakage and the like away from said packing.

HENRY G. BOWERING. 

